To determine what drives participation in clinical trials with decentralised elements and to estimate trial participation probabilities for trials with different degrees of decentralisation.

Patient preference study using a discrete choice experiment.

Recruitment in primary, secondary, tertiary care and other settings in the Netherlands (NL), Austria (AT) and Germany (DE).

People with type 2 diabetes mellitus (T2DM) aged ≥18 years. A total of 787 people (NL n=276, AT n=265, DE n=246) participated in the study.

Preferences for participation in clinical trials with different options for location and type of contact with the study team, activities to perform by participant, use of digital technologies by participant, number of scheduled contacts, trial duration, known safety and efficacy of the drug.

How much was known about the safety and efficacy of the drug was the most important element in the decision whether to participate in a clinical trial in all countries. The trial duration, location and type of contact with the study team, and number of scheduled contacts were other important elements. Participation probabilities for hypothetical trial scenarios differed between countries, with the highest rates for a decentralised trial involving video contact (NL: 89%; AT: 99%; DE: 84%).

People with T2DM prefer to take part in clinical trials with decentralised approaches. Information on preferences can help trialists and protocol developers to design and plan future trials that integrate patients’ needs and thus reduce barriers to participation.